This invention is related to indexable ball nose end mills, and more particularly to means for clamping a cutting insert in a holder in which a pair of protuberances carried on a cap are received in a pair of recesses in the insert and a third protuberance is received in a recess in the holder body for precisely locating the insert in its cutting position.
Indexable ball nose end mills conventionally are clamped on the end of a tool holder by a fastener received through an opening through the insert. The problem is that the insert does not maintain its cutting tolerances after it has been reversed end-for-end to employ the opposite cutting edge.